1. Field of the Invention
This invention relates to a comparator circuit. More particularly, this invention relates to a static-type comparator circuit that compares the magnitude of two binary numbers and determines if the numbers are equal, or if one number is greater than or less than the other number.
2. Brief Description of the Related Technology
Comparators may be used for comparing the magnitude of binary numbers. FIG. 1 illustrates a static-type, magnitude comparator comprising adders and complementers. The comparator of FIG. 1 can determine if a first binary number (A) is equal to or less than a second binary number (B). FIG. 2a, on the other hand, illustrates a static-type, magnitude comparator using a pass logic function. The comparator of FIG. 2a compares a first binary number (A) with a second binary number (B) and determines if the first binary number (A) is either: (i) greater than the second binary number (B); or (ii) less than or equal to the second binary number (B). FIG. 2b illustrates the circuitry of each cell in the comparator of FIG. 2a. See Neil Weste and Karman Eshraghian, "Principles of CMOS VLSI Design, A Systems Perspective .sctn.8.2.9" (VLSI System Series, 1985), citing ELECTRONICS (McGraw-Hill Inc., Sep. 22, 1983), which is incorporated herein by reference.
One skilled in the art will appreciate that there is a need for a static-type, magnitude comparator that can compare a first binary number with a second binary number and determine if: (i) the first binary number is equal to the second binary number; (ii) the first binary number is greater than the second binary number; or (iii) the first binary number is less than the second binary number. Furthermore, there is a need for a static-type, magnitude comparator that not only makes these determinations but also includes timing circuitry for timing the comparator's operations.